Figure 5-8.Forehand welding.the direction of welding. The best method to use dependsupon the type of joint, joint position, and the need forheat control on the parts to be welded.FOREHAND WELDINGForehand welding (fig. 5-8) is often called PUD-DLE or RIPPLE WELDING. In this method of welding,the rod is kept ahead of the flame in the direction inwhich the weld is being made. You point the flame inthe direction of travel and hold the tip at an angle ofabout 45 degrees to the working surfaces. This flameposition preheats the edges you are welding just aheadof the molten puddle. Move the rod in the same directionas the tip, and by moving the torch tip and the weldingrod back and forth in opposite, semicircular paths, youcan distribute the heat evenly. As the flame passes thewelding rod, it melts a short length of the rod and addsit to the puddle. The motion of the torch distributes themolten metal evenly to both edges of the joint and to themolten puddle.The forehand method is used in all positions forwelding sheet and light plate up to 1/8 of an inch thick.This method is ideal because it permits better control ofa small puddle and results in a smoother weld. Theforehand technique is not recommended for weldingheavy plate due to its lack of base metal penetration.BACKHAND WELDINGIn backhand welding (fig. 5-9), the torch tip pre-cedes the rod in the direction of welding and the flamepoints back at the molten puddle and completed weld.The welding tip should make an angle of about 60degrees with the plates or joint being welded. The endof the welding rod is placed between the torch tip andthe molten puddle.Figure 5-9.Backhand welding.Less motion is used in the backhand method than inthe forehand method. If you use a straight welding rod,you should rotate it so the end rolls from side to side andmelts off evenly. You might have to bend the rod whenworking in confined spaces. If you do, it becomes diffi-cult to roll a bent rod, and to compensate, you have tomove the rod and torch back and forth at a rather rapidrate. When making a large weld, you should move therod so it makes complete circles in the molten puddle.The torch is moved back and forth across the weld whileit is advanced slowly and uniformly in the direction ofthe welding.The backhand method is best for welding materialmore than 1/8 of an inch thick. You can use a narrowervee at the joint than is possible in forehand welding. Anincluded angle of 60 degrees is a sufficient angle ofbevel to get a good joint. The backhand method requiresless welding rod or puddling as the forehand method.By using the backhand technique on heavier mate-rial, you can increase your welding speed, better yourcontrol of the larger puddle, and have more completefusion at the weld root. If you use a slightly reducingflame with the backhand technique, a smaller amount ofbase metal is melted while welding the joint. When youare welding steel with a backhand technique and aslightly reducing flame, the absorption of carbon by athin surface layer of metal reduces the melting point ofthe steel. This speeds up the welding operation, Thistechnique is also used in surfacing with chromium-co-balt alloys.MULTILAYER WELDING is used in order toavoid carrying too large a puddle of molten metal whenwelding thick plate and pipe. Large puddles are difficultto control. Concentrate on getting a good weld at thebottom of the vee in the first passe Then, in the next5-7